Fair Value Measurements - Fair Value of Assets Required to be Measured at Fair Value (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Items Measured at Fair Value on a Non-recurring Basis
Total Adjustments Loss/(Gain) - Intangible and Tangible Assets	$ 100.8	$ 20.0
Fair Value, Measurements, Nonrecurring [Member]
Items Measured at Fair Value on a Non-recurring Basis
Intangible and tangible assets	81.4
Total Adjustments Loss/(Gain) - Intangible and Tangible Assets	97.1
Contingent earnout liabilities	97.3
Total Adjustments Loss/(Gain) - Contingent Earnout Liabilities	0.7
Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member]
Items Measured at Fair Value on a Non-recurring Basis
Intangible and tangible assets	0
Contingent earnout liabilities	0
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member]
Items Measured at Fair Value on a Non-recurring Basis
Intangible and tangible assets	0
Contingent earnout liabilities	0
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member]
Items Measured at Fair Value on a Non-recurring Basis
Intangible and tangible assets	81.4
Contingent earnout liabilities	$ 97.3